The present invention relates generally to anti-skid systems for automobile vehicles. Means have been provided in the past for detecting the relative slowdown of a vehicle wheel which occurs in a skid to produce a skid signal and for utilizing such signal to relieve braking pressure at the particular wheel. Such anti-skid systems have predominantly utilized electronically generated signals. The means for generating and responding to such signals tend to be complex and costly. Such systems are characterized by hair trigger sensitivity, and general lack of reliability, and are subject to changes in braking characteristics as changes occur in the electronic components of which the system is composed.
Resort has been had to using air as the signalling medium, but air systems are equally unreliable and disadvantageous for other reasons.
Prior anti-skid systems, moreover, tend to hunt, that is, tend to act cyclically, rather than proportionately, shifting back and forth from a skidding to a non-skidding condition at a rapid rate. In short, prior systems are not capable of achieving a condition in which braking is stably maintained at a level which will produce, and hold, a slip of small but predetermined percentage for maximum, skid-free braking effect.